To say that I am truly uninspired this morning just about sums it up, it was a long day yesterday and even though I didn’t get home until after 16:00 I did get much done, though I wish now that I’d done more, or at least done more of the outside jobs. The wood that I cut did not get brought in under cover so is now soaking wet, the stuff in the wheelbarrow is actually swimming. It has in short been pishing down since the early hours, if only I’d have cut bedding for the pigs last night and cleaned them out 😦 At least I managed to get our lawn done so that’s one thing,
for the sight that greeted me this morning would suggest that it’s on for the day and I won’t be cutting anything outside 😦
Changing ‘Harris Hydro turbine’ bearings
One major thing that I did do was go along to the ‘Old Schoolhouse’ at Torran http://www.uniquescotland.com/raasayschool/index.html to remove the Harris hydro turbine and change the bearings. This fine pelton wheel turbine https://lifeattheendoftheroad.wordpress.com/2008/02/07/the-harris-hydro-turbine/ developed by Don Harris in California. Originally based on a large car alternator it has now been refined into a powerful brushless battery charging system available in 12, 24, and 48v with output as high as 2500w on the 48v model. Don has sold the business but someone else has taken it over so spares and new units are readily available. This one came from Hugh Piggot of http://scoraigwind.com/ who can supply turbines and parts at competitive prices.
As this is in use 24/7 throughout the summer and I did not want it out of action any longer than necessary I turned to http://fieldlines.com/board/index.php/topic,143681.0.html for help and sure enough within a couple of days all was made clear, Chris supplied the part number of the bearing and http://www.onlinebearings.co.uk/ supplied two bearings very quickly and cheaply.
So with all the parts and armed with the knowledge that it would be a straight forward job I elected to remove the turbine last night and overhaul it in my workshop at home.
It had certainly become a bit of a jungle in the two weeks since I last visited.
This 24v unit is a four nozzle turbine but only three are used, a small 3mm one which produces about 150w and is used in times of drought or when the property is unattended. A 4mm nozzle which produces around 300w and is capable of supplying the properties entire electrical needs unless some clown brings a toaster or hair drier on holiday, in which case the diesel generator will auto start 😦 The largest, a 6mm nozzle can produce over 500w but is only used for short periods as the cable and rest of the system is not really designed for sustained usage at that current or water flow but it is a good way of quickly topping up the batteries 🙂
Once home my initial thoughts were that the pelton wheel would be seized onto the alternator shaft as it did look a little rusty in there.
Not at all a 5/16” (I think) Allen key is used to hold the shaft and the runner just turned anti clockwise with a pair of thick gloves or rag to stop getting your hands cut.
Once off remove the plate an spacers from below, taking note of their order,
remove the base (two Allen screws) and the alternator top (three small ones)
Tap out the rotor, remove the three screws and washers that secure the bottom bearing and drift it out. The top bearing will apparently last forever and just require a dab of high melting point grease whenever the lower one is changed. Assembly is just a simple reversal though make sure you fit the first large washer to the shaft before you bolt on the base.
Anyway, that was it really, it’s now 8:00am, wetter and even more miserable than it was when I started writing this an hour or so ago and now I have to go back out into the ‘rain forest’ and fit it 😦
and there’s a river running down my garden path 😦